HEADQUARTERS DISTRICT OF FLORIDA,
Jacksonville, Fla., August 4, 1864.

Major General J. G. FOSTER,

Commanding Department of the South:

GENERAL: I arrived here last night, having changed at the bar onto the Mary Benton. The Delaware got aground coming up the river. I sent down the Canonicus to lighten her. She took off the troops but could not draw her off. The troops were brought up and the boat sent back to take out the cargo. I hope she will get off and up here to-night. The Eighth U. S. Colored Troops had been sent to Palatka, where they arrived just in time to save a detachment of 25 cavalry left at that place. They were driven into the intrenchments with a loss of 1 officer and 2 privates prisoners. All are now withdrawn. I have sent out to Baldwin the Thirty-fourth and One hundred and second U. S. Colored Troops, and ordered in the Seventh U. S. Colored Troops. They will be in and embark to-morrow for the Head.

And now about the campaign. General Birney is very sanguine, and I do not doubt that had the movement been made in force we could have occupied the country to the Suwannee. To do it there will be required three or four more regiments and another battery. I think Birney's plans are good, but a large, force will be required.

I have had to-day a conversation with a Colonel Wilson, a refugee, just in from Alachua County. He appears a very strong Union man, and has the reputation of having been one throughout the war. He is very desirous of having us occupy the country, but says do not attempt it with an insufficient force. Seymour's defeat he says hurt the cause very much. About 500 Union men, deserters, and negroes are in the vicinity of Cedar Keys, and are now raiding toward Gainesville. The people confidently expect re-enforcements will be sent to Florida. It is thought none have yet arrived. The present force is variously estimated at from 1,000 to 2,000 men. The infantry are mostly the "new issue." I shall advance the force at Baldwin to Barber's and take up the rails of the road from that point to Baldwin. If you think I had better try the raid through Alachua and Marion I will by that time be re-enforced and will try the thing. You will yourself be better able to learn than I can do what chance there is of the enemy sending troops are. The locomotive met with an accident yesterday; it was thrown from the track and somewhat injured; how, much, I cannot learn, as it has not yet been got on the track. The rails had been loosened by the rebels. General Birney was in the car. No one was injured.

Can you not persuade some of the submarine fellows to come here and get the Saint Mary's up? She is a fine vessel and is not injured. The navy will never do it and are not trying.

I shall immediately occupy Magnolia and build a small work there. I will not complete the work at Baldwin, which, by the way, was not commenced until General Birney's return from Hilton Head.

If Sherman has thoroughly beaten Hood it is not probable that any troops can be spared by the rebels for Florida.

Very respectfully, your obedient servant,

JNO. P. HATCH,

Brigadier-General.

One section of artillery additional would be sufficient.